Answer:
Meiosis is a type of cell division that produces gametes.
Explanation:
Gametes are haploid cells, and each cell carries only one copy of each chromosome. These reproductive cells are produced through a type of cell division called meiosis.
The correct answer is option A. They either match up with a receptor molecule on the surface of the cell or enter the cell through the membrane.
The intercellular signals are the signals, which transfer the signals from one cell to the another and the intracellular signals are those signals, which carries message within the cell.
The intercellular signals may or may not be transferred through the gap junctions. The chemical signals are one of the type of the cell signals. The chemical signalling molecules generally have a receptor on the cells, where these molecules can bind and can be cause the activation of the cell. The chemical signals can also enter into the cells through active transport and facilitated diffusion. So, these type of transports does not go through the Gap junction.
Answer: To eliminate bacteria that failed to take in the plasmid.
Explanation:
Research shows that plasmid DNA is only taken in by small percentage of bacteria in a large population.
Therefore, the need of growing transformed bacteria in the presence of ampicillin is very important. The main reason of this process is to kill off or eliminate bacteria that have failed to take in the plasmid, due to their possession of recombinant DNA plasmid pARA-R (an ampicillin resistance gene), that allows them to survive.
However, after completion of the aforementioned procedure, the bacteria that have been transformed will be able to take in the plasmid.
Answer:
C. Ringed seal
Explanation:
A marine food web illustrates how energy is passed from one organism (level) to another in this aquatic rich ecosystem.
In the following food web, the interaction goes like this:
- The Arctic cod feeds on plankton and silverslides and it is preyed upon beluga whales and ringed seals.
- The sea duck goes to the bottom of the ocean to feed on benthic organisms and also consumes plankton and silverslides. It doesn't really have predators.
- The beluga whale doesn't really have predators, but it feeds on fish such as silverslades and Arctic cod.
- Ringed seals feed on plankton and Arctic cod and are then consumed by polar bears.
Therefore, according to this information, all organisms except the ringed seal feed directly on silverslides.
Q1. Pedigree is the recorded lineage of a family. A pedigree chart is actually a diagram showing an appearance and occurrence of phenotypes in several generations. It is used to find a probability of a child inheriting a particular trait or to discover is the trait autosomal or sex-related.
Q2. The presence of a trait in a pedigree chart is shown as filled-in figure. If a square or a circle in the pedigree chart are white (empty), then a person does not have a particular trait. If a figure is filled in (usually black), then a person has a trait. If a figure is half-filled in (e.g. it is half black half white), then a person is only a carrier of a trait but the trait is not expressed.
Q3. In the pedigree charts, squares present males and circles present females. If a female is healthy, the circle is empty (white). If a female is affected with a trait, the circle is filled in (usually black). Similarly, if a male is healthy, the square is empty. If a male is affected with a trait, the square is filled in.
Q4. The presence of dimples is a dominant trait. <span>In dominant traits, traits do not skip generations, unlike recessive traits. From the pedigree, the disorder did not skip any generations. This suggests that the disorder is dominant. If it was recessive, in some generation the trait would not be expressed.
Q5. If a pedigree chart of a family is known, then the occurrence and appearance of a trait can be predicted. For example, if it is known whether a disease is dominant, recessive, or sex-linked, then a possibility of getting a child with a disease can be easily calculated.</span>
